Method and device for assembling a hot top



Oct. 5, 1965 D. F. EDNELL METHOD AND DEVICE FOR ASSEMBLING A HOT TOP Filed May 7, 1963 2 Sheets-Sheet 1 Fig.1

Fig.2

INVENTOR ATTORNEYS Oct. 5, 1965 D. F. EDNELL 3,209,413

METHOD AND DEVICE FOR ASSEMBLING A HOT TOP Filed May 7, 1963 2 Sheets-Sheet 2 Fig.3

Fig.4

INVENTOR 9W6 FM BY Pun M 4244 s fiwjwb ATTORNEYS United States Patent 3,209,413 METHOD AND DEVICE FOR ASSEMBLING A HOT TOP Daniel Fredrik Ednell, Ed, Sweden, assignor to Sandvikens .lernverks Aktiebolag, Sandviken, Sweden, a corporation of Sweden Filed May 7, 1963, Ser. No. 278,657 Claims priority, application Sweden, May 9, 1962, 5,184/62 6 Claims. (Cl. 22-31) The present invention relates to a method for assembling a hot top consisting of separate relatively thin, heat insulating slabs at the upper part of the inside of an ingot mold or other casting mold, said hot top being designed to be assembled so that the slabs are held in contact with the mold by the pressure exerted between the pieces of the hot top. The invention also relates to a device for performing the said method.

It is important that a hot top has a tight contact with the mold along the lower edge of the hot top, because otherwise the cast metal will intrude between the hot top and the mold causing the formation of fins, which complicate the removal of the hot top after the casting and also cause difficulties in the rolling of the ingot.

A common type of hot top consists of slabs which are mounted along the upper edge of the mold with wedges inserted between them, preferably in the corners of the mold. The wedge pressure holds the slabs in the desired position so that the slabs at least at their lower edges are kept in tight contact with the mold. There are also hot tops without separate wedges, the slabs or some of the slabs being wedge shaped, so that the slabs exert a mutual wedge action on each other.

When assembling hot tops of this kind it has been found difficult to maintain the slabs in such a position during the fastening that their lower edges remain in tight contact with the wall of the mold. As there are several slabs in the hot top it is diflicult to keep all of them in tight contact with the mold when the wedge pressure is applied. The slabs are, by the wedge effect locked in the position which they have during the fastening and if the lower edges of any of them is spaced from the wall, the gap between the slab and wall will be present during the casting. It is also desirable that said contact is established under a certain amount of pressure in order to have it as tight as possible. contact with the mold before and during the application of the wedge pressure so that this contact will be maintained when the wedge pressure is applied and the slabs are locked against movement. This is achieved by applying a temporary sideward pressure on the slabs so that they all are simultaneously held in the desired position during the application of the wedge pressure. After locking the slabs by the wedge pressure the temporary sideward pressure is removed.

The invention is characterized in that the slabs during the assembling of the hot top are urged outwardly by aid of a separate expansible pressure device which is removed after the assembling.

Other features and advantages of the invention will appear from the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a longitudinal sectional view of the upper end portion of an ingot mold on the line 11 in FIG. 2 with an embodiment of the invention applied therein.

FIG. 2 is a top elevational view of the ingot mold in FIG. 1.

FIG. 3 is a fragmentary horizontal section on an enlarged scale of a modification of the ingot mold illusstrated in FIGS. 1 and 2.

FIG. 4 is a longitudinal sectional view of the upper The invention aims at holding all the slabs in "Ice portion of an ingot mold showing a second embodiment of the invention.

FIG. 1 shows a vertical section of an ingot mold 10. In the ingot mold is mounted a hot top consisting of slabs 11 and wedges 12 in the corners. When mounting the hot top the slabs 11 are hung by integral flanges 13 or other suitable means such as hooks (not shown) around the edge of the ingot mold after which the wedges 12 are inserted and pressed downwardly. As appears from FIG. 1 the contact surfaces 14 between the wedges and the slabs are inclined to vertical so that the wedges taper downwardly. From FIG. 2 it can be seen that the contact surfaces 14 are convergent in the horizontal plane towards the interior of the mold so that the slabs are prevented from moving away from the walls of the mold. In order to achieve the best possible tightening of the lower edges of the slabs against the wall of the mold the slabs are provided with a raised portion forming a tightening ridge 15 which is held in contact with the wall of the mold.

When a hot top is mounted in accordance with the invention a pressure device 20 is placed within the hot top, said device having about the same shape as the inner horizontal section of the hot top and being expansible in order to urge the slabs towards the mold. In the embodiment shown in FIGS. 1 and 2 the pressure device comprises a frame 21 around the periphery of which is fastened an air tight flexible tube 22 of rubber or the like. The device is provided with a carrying handle 23. For supplying compressed air or other compressed gas to the tube 22 a gas container 24 is fastened to the handle and is connected to a valve 25 by a tube 29. The valve 25 is operated by an operating handle 26 and by changing the position of the valve stem 27 the valve can be adapted either to supply gas to the tube 22 through the pipes 29, 28 or to let gas out from the tube 22 through the tube 28 to the atmosphere. Instead of having a container 24 fastened to the device it is of course possible to use a container situated beside the mold and to connect it to the valve by a flexible tube.

The construction of the valve forms no part of the invention, and as the same easily can be constructed by a person skilled in the art, only its functions are mentioned without showing any details of its construction. The operating handle 26 is held in the position shown in FIG. 1 for instance by a spring and is operated by pressing it downwardly. The operating handle 26 can be operated by the same hand that holds the device by the carrying handle 23.

When the pressure device 20 is placed within the hot top the flexible tube 22 must be deflated.

The valve stem 27 is positioned for supplying gas from the container 24 to the tube 22. When the slabs have been positioned in the mold the pressure device 20 is held by the carrying handle 23 in the position shown in FIG. 1, the tube 22 being in level with the lower edges of the slabs. Thereafter the handle 26 is operated and gas flows from the container 24 into the tube 22 and the tube is filled with compressed gas and its outer surface urges the slabs towards the wall of the mold. When suflicient pressure is achieved in the flexible tube 20 the handle 26 is released. It is thereafter not necessary to support the pressure device by the handle 23 as it is self-supported by the friction against the slabs.

Thereafter the wedges 12 are inserted and fastened. The valve stem 27 is then moved to its discharge position and when the operating handle is pressed downwardly the pressure gas is let out from the tube 22 whereafter the whole device can be removed from the mold.

The idea of the invention is to hold the slabs in firm contact with the mold especially at their lower edges during the fastening in order that this contact will be maintained by locking the slabs in this position by aid of the friction and pressure between the pieces of the hot top which arises when the Wedges are driven in. In this way not only are undesired gaps between the slabs and the mold avoided but at least a part of the contact pressure which is established by the pressure device is maintained. This contact pressure will remain also after removal of the pressure device so that the slabs are locked in their positions. Obviously the tightening contact will in this way be better than when the slabs, during the assembling of the hot top, are held only by manual force.

In order to limit the expansion of the flexible tube in the vicinity of the corners of the. hot top so that the flexible tube does not prevent the insertion of the wedges, the tube can be provided with metal bands 30 embracing the tube and preventing expansion thereof at the corners.

In FIGS. 1 and 2 the slabs and the mold wall are shown as being substantially plane. In FIG. 3 is shown, as a partial horizontal section, a corrugated ingot mold 40 with a correspondingly corrugated hot top slab 41. A flexible pressure tube 42 is fastened on a frame 43 and when inflated urges the hot top slab 41 against the wall 40 of the mold. The periphery of the tube follows the corrugations of the slab so that a relatively evenly distributed pressure is applied along the slab.

In FIG. 4 is shown an embodiment of the pressure device having mechanically expandible means instead of the flexible tube. A frame 50 is provided with radially directed bores in which are situated sliding rods 51. At the outer end of each rod is fastened a plate 52 provided with a cushion 53, which is intended to be positioned along the lower edge of the slab. The pressure is achieved by aid of a wedge shaped body 54 having inclined surfaces in contact with the inner ends of the rods 51. The body 54 is carried by a screw 55 rotatably connected to the body, the screw being positioned in a threaded sleeve 56 connected to the frame 50 by a bracket 58. The screw has a handle 57 for turning it.

This device shown in FIG. 4 is used in principally the same way as the devices shown in FIGS. 1-3. The pressure is applied by turning the handle 57 and during the turning the device can be held by the bracket 58. The mechanical tensioning device comprising the wedge shaped body 54 and the screw 55 can of course be substituted by any other suitable device as for instance a link mechanism for moving the cushions 53 outwardly.

In case the hot top comprises slabs only and the corner wedges are not used some of said slabs can be wedge shaped and can be loosely put in place when the hot top is assembled, whereafter the pressure device is applied and the wedge shaped slabs are driven in to their final position thereby locking the slabs of the hot top against movement. This type 'of hot top, like the hot top using corner wedges is well known.

The invention is not limited to the above described embodiments, which are only examples of how the in- 4 vention can be performed within the scope of the following claims. I claim:

1. Method of assembling a hot top consisting of a plurality of slabs and wedges in a casting mold which comprises supporting said slabs against the wall of the mold adjacent to the upper end thereof, expanding an expandible pressure means simultaneously outwardly against all of said slabs adjacent to the lower edges thereof, thereby tightening said edges against the wall of the mold, fixing said slabs in said tightened position by inserting and driving in said wedges between the adjacent edges thereof and retracting and withdrawing said expandible pressure means.

2. Method as defined in claim 1 in which said expandible pressure means is an inflatable and deflatable hollow flexible member.

3. Method as defined in claim 1 in which said expandible pressure means comprises a plurality of cushions, one for each slab, and means for urging said cushions against said slabs.

4. Method as defined in claim 1 in which said wedges are situated in the corners of the hot top.

5. Method as defined in claim 1 in which said wedges are wedge shaped slabs.

6. A device adapted for use in positioning a hot top comprising a plurality of slabs in a casting mold comprising a frame, a plurality of rods slidably supported by said frame and extending outwardly from adjacent the center of said frame, a flexible pad carried on the outer end of each rod and means carried by said frame for simultaneously moving said rods outwardly to force said pads against the slabs of the hot top.

References Cited by the Examiner UNITED STATES PATENTS 581,209 4/97 Hughes 279-2 963,603 7/10 Lanceford 269-48.1 1,312,615 8/19 Cooper 25128 1,571,424 2/26 Marx 25-128 2,579,801 12/51 Crom et al 25128 2,750,629 6/53 Baudou 25--128 XR 2,952,886 9/60 Mazarakis 229 3,077,646 2/63 Tigerschiold 25128 3,092,883 6/63 Ednell 22147 3,095,618 7/63 Roussos 229 3,171,169 3/65 Graef 229 FOREIGN PATENTS 17,706 8/ 13 Great Britain. 360,146 11/31 Great Britain.

1. SPENCER OVERHOLSER, Primary Examiner.

ROBERT F. WHITE, WILLIAM J. STEPHENSON,

MARCUS U. LYONS, Examiners. 

1. METHOD OF ASSEMBLING A HOT TOP CONSISTING OF A PLURALITY OF SLABS AND WEDGES IN A CASTING MOLD WHICH COMPRISES SUPPORTIONG SAID SLABS AGAINST THE WALL OF THE MOLD ADJACENT TO THE UPPER END THEREOF, EXPANDING AN EXPANDIBLE PRESSURE MEANS SIMULTANEOUSLY OUTWARDLY AGAINST ALL OF SAID SLABS ADJACENT TO THE LOWER EDGES THEREOF, THEREBY TIGHTENING SAID EDGES AGAINST THE WALL OF THE MOLD, FIXING SAID SLABS IN SAID TIGHTENED POSITION BY INSERTING AND DRIVING IN SAID WEDGES BETWEEN THE ADJACENT EDGES THEREOF AND RETRACTING AND WITHDRAWING SAID EXPANDIBLE PRESSURE MEANS.
 6. A DEVICE ADAPTED FOR USE IN POSITIONING A HOT TOP COMPRISING A PLURALITY OF SLABS IN A CASTING MOLD COMPRISING A FRAME, A PLURALITY OF RODS SLIDABLY SUPPORTED BY SAID FRAME AND EXTENDING OUTWARDLY FROM ADJACENT THE CENTER OF SAID FRAME, A FLEXIBLE PAD CARRIED ON THE OUTER END OF EACH ROD AND MEANS CARRIED BY SAID FRAME FOR SIMULTANEOUSLY MOVING SAID RODS OUTWARDLY TO FORCE SAID PADS AGAINST SLABS OF THE HOT TOP. 